<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../react18/react.development.js"></script>
  <script src="../react18/react-dom.development.js"></script>
  <script src="../react18/babel.min.js"></script>
</head>

<body>
  <div id="app"></div>
  <script type="text/babel">

    /* 
      当表单的value受state控制,则我们称作为受控表单   state保存数据
        -受控表单的三种用法
          1.表单的初始值受控  直接书写defaultValue属性
          2.表单是只读表单(设置了readOnly={true}) 直接设置value也是可以的
          3.数据双向绑定:表单通过value受控,然后需要绑定onChang事件,事件中获取当前表单的值修改state
    */

   
    class App  extends React.Component{
      state={
        name:"laowang ",
        age:18,
        hobby:'吃饭'
      }

      render(){
        // 拿值就是结构
        const{name,age,hobby}=this.state
        return (
          <div>
            姓名:<input type="text" defaultValue={name} />
            <br/>
            年龄:<input type="text" value={age} />
            <br/>
            爱好:<input type="text"  value={hobby}/>
            <br/>
            <button onClick={this.handle}>提交</button>
            </div>
        )
      }

      handle=()=>{

      }
    }

    const root=ReactDOM.createRoot(document.getElementById('app'))
    root.render(<App/>)
  </script>
</body>

</html>